These patch leads are terminated at one end with a 4mm plug and at the other end with a 3.5mm plug making them ideal for patching between systems with these different formats such as between 4U Serge and 3.5mm EuroRack or 3U EuroSerge (4mm) and 3U EuroRack.
NB: These patch leads do not incorporate a 0V/Shield/Screen, when patching between separately powered systems you will need to add a 0V Reference connection between the systems